1 files changed, 641 insertions, 0 deletions

diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
new file mode 100644
index 000000000..7b9688897
--- /dev/null
+++ b/arch/s390/kernel/topology.c
@@ -0,0 +1,641 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *    Copyright IBM Corp. 2007, 2011
+ *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
+ */
+
+#define KMSG_COMPONENT "cpu"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/workqueue.h>
+#include <linux/bootmem.h>
+#include <linux/uaccess.h>
+#include <linux/sysctl.h>
+#include <linux/cpuset.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/sched/topology.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <linux/mm.h>
+#include <linux/nodemask.h>
+#include <linux/node.h>
+#include <asm/sysinfo.h>
+#include <asm/numa.h>
+
+#define PTF_HORIZONTAL	(0UL)
+#define PTF_VERTICAL	(1UL)
+#define PTF_CHECK	(2UL)
+
+enum {
+	TOPOLOGY_MODE_HW,
+	TOPOLOGY_MODE_SINGLE,
+	TOPOLOGY_MODE_PACKAGE,
+	TOPOLOGY_MODE_UNINITIALIZED
+};
+
+struct mask_info {
+	struct mask_info *next;
+	unsigned char id;
+	cpumask_t mask;
+};
+
+static int topology_mode = TOPOLOGY_MODE_UNINITIALIZED;
+static void set_topology_timer(void);
+static void topology_work_fn(struct work_struct *work);
+static struct sysinfo_15_1_x *tl_info;
+
+static DECLARE_WORK(topology_work, topology_work_fn);
+
+/*
+ * Socket/Book linked lists and cpu_topology updates are
+ * protected by "sched_domains_mutex".
+ */
+static struct mask_info socket_info;
+static struct mask_info book_info;
+static struct mask_info drawer_info;
+
+struct cpu_topology_s390 cpu_topology[NR_CPUS];
+EXPORT_SYMBOL_GPL(cpu_topology);
+
+cpumask_t cpus_with_topology;
+
+static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
+{
+	cpumask_t mask;
+
+	cpumask_copy(&mask, cpumask_of(cpu));
+	switch (topology_mode) {
+	case TOPOLOGY_MODE_HW:
+		while (info) {
+			if (cpumask_test_cpu(cpu, &info->mask)) {
+				mask = info->mask;
+				break;
+			}
+			info = info->next;
+		}
+		if (cpumask_empty(&mask))
+			cpumask_copy(&mask, cpumask_of(cpu));
+		break;
+	case TOPOLOGY_MODE_PACKAGE:
+		cpumask_copy(&mask, cpu_present_mask);
+		break;
+	default:
+		/* fallthrough */
+	case TOPOLOGY_MODE_SINGLE:
+		cpumask_copy(&mask, cpumask_of(cpu));
+		break;
+	}
+	return mask;
+}
+
+static cpumask_t cpu_thread_map(unsigned int cpu)
+{
+	cpumask_t mask;
+	int i;
+
+	cpumask_copy(&mask, cpumask_of(cpu));
+	if (topology_mode != TOPOLOGY_MODE_HW)
+		return mask;
+	cpu -= cpu % (smp_cpu_mtid + 1);
+	for (i = 0; i <= smp_cpu_mtid; i++)
+		if (cpu_present(cpu + i))
+			cpumask_set_cpu(cpu + i, &mask);
+	return mask;
+}
+
+#define TOPOLOGY_CORE_BITS	64
+
+static void add_cpus_to_mask(struct topology_core *tl_core,
+			     struct mask_info *drawer,
+			     struct mask_info *book,
+			     struct mask_info *socket)
+{
+	struct cpu_topology_s390 *topo;
+	unsigned int core;
+
+	for_each_set_bit(core, &tl_core->mask, TOPOLOGY_CORE_BITS) {
+		unsigned int rcore;
+		int lcpu, i;
+
+		rcore = TOPOLOGY_CORE_BITS - 1 - core + tl_core->origin;
+		lcpu = smp_find_processor_id(rcore << smp_cpu_mt_shift);
+		if (lcpu < 0)
+			continue;
+		for (i = 0; i <= smp_cpu_mtid; i++) {
+			topo = &cpu_topology[lcpu + i];
+			topo->drawer_id = drawer->id;
+			topo->book_id = book->id;
+			topo->socket_id = socket->id;
+			topo->core_id = rcore;
+			topo->thread_id = lcpu + i;
+			topo->dedicated = tl_core->d;
+			cpumask_set_cpu(lcpu + i, &drawer->mask);
+			cpumask_set_cpu(lcpu + i, &book->mask);
+			cpumask_set_cpu(lcpu + i, &socket->mask);
+			cpumask_set_cpu(lcpu + i, &cpus_with_topology);
+			smp_cpu_set_polarization(lcpu + i, tl_core->pp);
+		}
+	}
+}
+
+static void clear_masks(void)
+{
+	struct mask_info *info;
+
+	info = &socket_info;
+	while (info) {
+		cpumask_clear(&info->mask);
+		info = info->next;
+	}
+	info = &book_info;
+	while (info) {
+		cpumask_clear(&info->mask);
+		info = info->next;
+	}
+	info = &drawer_info;
+	while (info) {
+		cpumask_clear(&info->mask);
+		info = info->next;
+	}
+}
+
+static union topology_entry *next_tle(union topology_entry *tle)
+{
+	if (!tle->nl)
+		return (union topology_entry *)((struct topology_core *)tle + 1);
+	return (union topology_entry *)((struct topology_container *)tle + 1);
+}
+
+static void tl_to_masks(struct sysinfo_15_1_x *info)
+{
+	struct mask_info *socket = &socket_info;
+	struct mask_info *book = &book_info;
+	struct mask_info *drawer = &drawer_info;
+	union topology_entry *tle, *end;
+
+	clear_masks();
+	tle = info->tle;
+	end = (union topology_entry *)((unsigned long)info + info->length);
+	while (tle < end) {
+		switch (tle->nl) {
+		case 3:
+			drawer = drawer->next;
+			drawer->id = tle->container.id;
+			break;
+		case 2:
+			book = book->next;
+			book->id = tle->container.id;
+			break;
+		case 1:
+			socket = socket->next;
+			socket->id = tle->container.id;
+			break;
+		case 0:
+			add_cpus_to_mask(&tle->cpu, drawer, book, socket);
+			break;
+		default:
+			clear_masks();
+			return;
+		}
+		tle = next_tle(tle);
+	}
+}
+
+static void topology_update_polarization_simple(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		smp_cpu_set_polarization(cpu, POLARIZATION_HRZ);
+}
+
+static int ptf(unsigned long fc)
+{
+	int rc;
+
+	asm volatile(
+		"	.insn	rre,0xb9a20000,%1,%1\n"
+		"	ipm	%0\n"
+		"	srl	%0,28\n"
+		: "=d" (rc)
+		: "d" (fc)  : "cc");
+	return rc;
+}
+
+int topology_set_cpu_management(int fc)
+{
+	int cpu, rc;
+
+	if (!MACHINE_HAS_TOPOLOGY)
+		return -EOPNOTSUPP;
+	if (fc)
+		rc = ptf(PTF_VERTICAL);
+	else
+		rc = ptf(PTF_HORIZONTAL);
+	if (rc)
+		return -EBUSY;
+	for_each_possible_cpu(cpu)
+		smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
+	return rc;
+}
+
+static void update_cpu_masks(void)
+{
+	struct cpu_topology_s390 *topo;
+	int cpu, id;
+
+	for_each_possible_cpu(cpu) {
+		topo = &cpu_topology[cpu];
+		topo->thread_mask = cpu_thread_map(cpu);
+		topo->core_mask = cpu_group_map(&socket_info, cpu);
+		topo->book_mask = cpu_group_map(&book_info, cpu);
+		topo->drawer_mask = cpu_group_map(&drawer_info, cpu);
+		if (topology_mode != TOPOLOGY_MODE_HW) {
+			id = topology_mode == TOPOLOGY_MODE_PACKAGE ? 0 : cpu;
+			topo->thread_id = cpu;
+			topo->core_id = cpu;
+			topo->socket_id = id;
+			topo->book_id = id;
+			topo->drawer_id = id;
+			if (cpu_present(cpu))
+				cpumask_set_cpu(cpu, &cpus_with_topology);
+		}
+	}
+	numa_update_cpu_topology();
+}
+
+void store_topology(struct sysinfo_15_1_x *info)
+{
+	stsi(info, 15, 1, topology_mnest_limit());
+}
+
+static void __arch_update_dedicated_flag(void *arg)
+{
+	if (topology_cpu_dedicated(smp_processor_id()))
+		set_cpu_flag(CIF_DEDICATED_CPU);
+	else
+		clear_cpu_flag(CIF_DEDICATED_CPU);
+}
+
+static int __arch_update_cpu_topology(void)
+{
+	struct sysinfo_15_1_x *info = tl_info;
+	int rc = 0;
+
+	mutex_lock(&smp_cpu_state_mutex);
+	cpumask_clear(&cpus_with_topology);
+	if (MACHINE_HAS_TOPOLOGY) {
+		rc = 1;
+		store_topology(info);
+		tl_to_masks(info);
+	}
+	update_cpu_masks();
+	if (!MACHINE_HAS_TOPOLOGY)
+		topology_update_polarization_simple();
+	mutex_unlock(&smp_cpu_state_mutex);
+	return rc;
+}
+
+int arch_update_cpu_topology(void)
+{
+	struct device *dev;
+	int cpu, rc;
+
+	rc = __arch_update_cpu_topology();
+	on_each_cpu(__arch_update_dedicated_flag, NULL, 0);
+	for_each_online_cpu(cpu) {
+		dev = get_cpu_device(cpu);
+		if (dev)
+			kobject_uevent(&dev->kobj, KOBJ_CHANGE);
+	}
+	return rc;
+}
+
+static void topology_work_fn(struct work_struct *work)
+{
+	rebuild_sched_domains();
+}
+
+void topology_schedule_update(void)
+{
+	schedule_work(&topology_work);
+}
+
+static void topology_flush_work(void)
+{
+	flush_work(&topology_work);
+}
+
+static void topology_timer_fn(struct timer_list *unused)
+{
+	if (ptf(PTF_CHECK))
+		topology_schedule_update();
+	set_topology_timer();
+}
+
+static struct timer_list topology_timer;
+
+static atomic_t topology_poll = ATOMIC_INIT(0);
+
+static void set_topology_timer(void)
+{
+	if (atomic_add_unless(&topology_poll, -1, 0))
+		mod_timer(&topology_timer, jiffies + HZ / 10);
+	else
+		mod_timer(&topology_timer, jiffies + HZ * 60);
+}
+
+void topology_expect_change(void)
+{
+	if (!MACHINE_HAS_TOPOLOGY)
+		return;
+	/* This is racy, but it doesn't matter since it is just a heuristic.
+	 * Worst case is that we poll in a higher frequency for a bit longer.
+	 */
+	if (atomic_read(&topology_poll) > 60)
+		return;
+	atomic_add(60, &topology_poll);
+	set_topology_timer();
+}
+
+static int cpu_management;
+
+static ssize_t dispatching_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	ssize_t count;
+
+	mutex_lock(&smp_cpu_state_mutex);
+	count = sprintf(buf, "%d\n", cpu_management);
+	mutex_unlock(&smp_cpu_state_mutex);
+	return count;
+}
+
+static ssize_t dispatching_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf,
+				 size_t count)
+{
+	int val, rc;
+	char delim;
+
+	if (sscanf(buf, "%d %c", &val, &delim) != 1)
+		return -EINVAL;
+	if (val != 0 && val != 1)
+		return -EINVAL;
+	rc = 0;
+	get_online_cpus();
+	mutex_lock(&smp_cpu_state_mutex);
+	if (cpu_management == val)
+		goto out;
+	rc = topology_set_cpu_management(val);
+	if (rc)
+		goto out;
+	cpu_management = val;
+	topology_expect_change();
+out:
+	mutex_unlock(&smp_cpu_state_mutex);
+	put_online_cpus();
+	return rc ? rc : count;
+}
+static DEVICE_ATTR_RW(dispatching);
+
+static ssize_t cpu_polarization_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	int cpu = dev->id;
+	ssize_t count;
+
+	mutex_lock(&smp_cpu_state_mutex);
+	switch (smp_cpu_get_polarization(cpu)) {
+	case POLARIZATION_HRZ:
+		count = sprintf(buf, "horizontal\n");
+		break;
+	case POLARIZATION_VL:
+		count = sprintf(buf, "vertical:low\n");
+		break;
+	case POLARIZATION_VM:
+		count = sprintf(buf, "vertical:medium\n");
+		break;
+	case POLARIZATION_VH:
+		count = sprintf(buf, "vertical:high\n");
+		break;
+	default:
+		count = sprintf(buf, "unknown\n");
+		break;
+	}
+	mutex_unlock(&smp_cpu_state_mutex);
+	return count;
+}
+static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
+
+static struct attribute *topology_cpu_attrs[] = {
+	&dev_attr_polarization.attr,
+	NULL,
+};
+
+static struct attribute_group topology_cpu_attr_group = {
+	.attrs = topology_cpu_attrs,
+};
+
+static ssize_t cpu_dedicated_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	int cpu = dev->id;
+	ssize_t count;
+
+	mutex_lock(&smp_cpu_state_mutex);
+	count = sprintf(buf, "%d\n", topology_cpu_dedicated(cpu));
+	mutex_unlock(&smp_cpu_state_mutex);
+	return count;
+}
+static DEVICE_ATTR(dedicated, 0444, cpu_dedicated_show, NULL);
+
+static struct attribute *topology_extra_cpu_attrs[] = {
+	&dev_attr_dedicated.attr,
+	NULL,
+};
+
+static struct attribute_group topology_extra_cpu_attr_group = {
+	.attrs = topology_extra_cpu_attrs,
+};
+
+int topology_cpu_init(struct cpu *cpu)
+{
+	int rc;
+
+	rc = sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
+	if (rc || !MACHINE_HAS_TOPOLOGY)
+		return rc;
+	rc = sysfs_create_group(&cpu->dev.kobj, &topology_extra_cpu_attr_group);
+	if (rc)
+		sysfs_remove_group(&cpu->dev.kobj, &topology_cpu_attr_group);
+	return rc;
+}
+
+static const struct cpumask *cpu_thread_mask(int cpu)
+{
+	return &cpu_topology[cpu].thread_mask;
+}
+
+
+const struct cpumask *cpu_coregroup_mask(int cpu)
+{
+	return &cpu_topology[cpu].core_mask;
+}
+
+static const struct cpumask *cpu_book_mask(int cpu)
+{
+	return &cpu_topology[cpu].book_mask;
+}
+
+static const struct cpumask *cpu_drawer_mask(int cpu)
+{
+	return &cpu_topology[cpu].drawer_mask;
+}
+
+static struct sched_domain_topology_level s390_topology[] = {
+	{ cpu_thread_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
+	{ cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
+	{ cpu_book_mask, SD_INIT_NAME(BOOK) },
+	{ cpu_drawer_mask, SD_INIT_NAME(DRAWER) },
+	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
+	{ NULL, },
+};
+
+static void __init alloc_masks(struct sysinfo_15_1_x *info,
+			       struct mask_info *mask, int offset)
+{
+	int i, nr_masks;
+
+	nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
+	for (i = 0; i < info->mnest - offset; i++)
+		nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
+	nr_masks = max(nr_masks, 1);
+	for (i = 0; i < nr_masks; i++) {
+		mask->next = memblock_virt_alloc(sizeof(*mask->next), 8);
+		mask = mask->next;
+	}
+}
+
+void __init topology_init_early(void)
+{
+	struct sysinfo_15_1_x *info;
+
+	set_sched_topology(s390_topology);
+	if (topology_mode == TOPOLOGY_MODE_UNINITIALIZED) {
+		if (MACHINE_HAS_TOPOLOGY)
+			topology_mode = TOPOLOGY_MODE_HW;
+		else
+			topology_mode = TOPOLOGY_MODE_SINGLE;
+	}
+	if (!MACHINE_HAS_TOPOLOGY)
+		goto out;
+	tl_info = memblock_virt_alloc(PAGE_SIZE, PAGE_SIZE);
+	info = tl_info;
+	store_topology(info);
+	pr_info("The CPU configuration topology of the machine is: %d %d %d %d %d %d / %d\n",
+		info->mag[0], info->mag[1], info->mag[2], info->mag[3],
+		info->mag[4], info->mag[5], info->mnest);
+	alloc_masks(info, &socket_info, 1);
+	alloc_masks(info, &book_info, 2);
+	alloc_masks(info, &drawer_info, 3);
+out:
+	__arch_update_cpu_topology();
+	__arch_update_dedicated_flag(NULL);
+}
+
+static inline int topology_get_mode(int enabled)
+{
+	if (!enabled)
+		return TOPOLOGY_MODE_SINGLE;
+	return MACHINE_HAS_TOPOLOGY ? TOPOLOGY_MODE_HW : TOPOLOGY_MODE_PACKAGE;
+}
+
+static inline int topology_is_enabled(void)
+{
+	return topology_mode != TOPOLOGY_MODE_SINGLE;
+}
+
+static int __init topology_setup(char *str)
+{
+	bool enabled;
+	int rc;
+
+	rc = kstrtobool(str, &enabled);
+	if (rc)
+		return rc;
+	topology_mode = topology_get_mode(enabled);
+	return 0;
+}
+early_param("topology", topology_setup);
+
+static int topology_ctl_handler(struct ctl_table *ctl, int write,
+				void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	int enabled = topology_is_enabled();
+	int new_mode;
+	int zero = 0;
+	int one = 1;
+	int rc;
+	struct ctl_table ctl_entry = {
+		.procname	= ctl->procname,
+		.data		= &enabled,
+		.maxlen		= sizeof(int),
+		.extra1		= &zero,
+		.extra2		= &one,
+	};
+
+	rc = proc_douintvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
+	if (rc < 0 || !write)
+		return rc;
+
+	mutex_lock(&smp_cpu_state_mutex);
+	new_mode = topology_get_mode(enabled);
+	if (topology_mode != new_mode) {
+		topology_mode = new_mode;
+		topology_schedule_update();
+	}
+	mutex_unlock(&smp_cpu_state_mutex);
+	topology_flush_work();
+
+	return rc;
+}
+
+static struct ctl_table topology_ctl_table[] = {
+	{
+		.procname	= "topology",
+		.mode		= 0644,
+		.proc_handler	= topology_ctl_handler,
+	},
+	{ },
+};
+
+static struct ctl_table topology_dir_table[] = {
+	{
+		.procname	= "s390",
+		.maxlen		= 0,
+		.mode		= 0555,
+		.child		= topology_ctl_table,
+	},
+	{ },
+};
+
+static int __init topology_init(void)
+{
+	timer_setup(&topology_timer, topology_timer_fn, TIMER_DEFERRABLE);
+	if (MACHINE_HAS_TOPOLOGY)
+		set_topology_timer();
+	else
+		topology_update_polarization_simple();
+	register_sysctl_table(topology_dir_table);
+	return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching);
+}
+device_initcall(topology_init);